Efeitos dos níveis de extrato etéreo no sucedâneo do leite sobre o desenvolvimento corporal de bezerros Jersey

Abstract

Utilizaram-se 20 bezerros Jersey com o objetivo de avaliar o efeito dos níveis de extrato etéreo no sucedâneo comercial sobre o peso corporal, o ganho de peso médio diário, a altura na cernelha, o perímetro torácico e o consumo de concentrado, do 8o ao 90o dia de idade, visando determinar o melhor nível de extrato etéreo. Os animais foram distribuídos nos tratamentos, que consistiram de quatro dietas líquidas: leite integral (T1), sucedâneo lácteo comercial padronizado com gordura suína para 10 (T2), 15 (T3) e 20% (T4) de extrato etéreo (EE) na matéria seca, de acordo com a seqüência de nascimento. O delineamento experimental utilizado foi o de blocos ao acaso com arranjo fatorial desbalanceado, em que os fatores foram a dieta (n=4) e o sexo (n=2). Os dados de desenvolvimento corporal e consumo de alimento foram submetidos à análise de variância. Aos 56 dias de idade, os bezerros alimentados com leite integral e sucedâneo a 10% EE apresentaram diferença significativa no peso corporal e no ganho de peso médio diário (8-56 dias). Os bezerros que receberam leite integral apresentaram maior perímetro torácico e, após o desaleitamento, medidas de peso corporal, ganhos de peso médio diário (57 a 89 dias), perímetro torácico e altura na cernelha superiores às dos que receberam o sucedâneo. Na fase de aleitamento, o sucedâneo a 10% EE promoveu ganho de peso superior ao sucedâneo a 15 e 20% de EE na matéria seca e ganho de peso similar ao leite integral.

Twenty Jersey calves were used to investigate the effects of different ether extract levels of a commercial milk replacer on body weight, average daily weight gain, height at withers, heart girth, and starter intake from the 8th to the 90th day after birth. It was of particular interest to determine the optimum milk replacer ether extract level. This trial was conducted at EMBRAPA Clima Temperado, CPACT, from October 2000 to May 2001. Animals were assigned, according to their birth date, to one of four liquid diets as follows: whole milk (T1) or milk replacer plus different proportions of lard to yield 10 (T2), 15 (T3) or 20% (T4) ether extract on dry matter basis. Statistical analysis was performed as a randomized complete block design with an unbalanced factorial arrangement and diets (n=4) and sex (n=2) as factors. Data from body development and starter intake were both submitted to analysis of variance. Body weight at 56 days of age and average daily weight gain from eight to 56 days post-calving were significantly higher for animals receiving T1 and T2 than for those fed T3 and T4 liquid diets. In addition, heart girth at 56 days of age was greater on calves fed whole milk than on those fed milk replacer with different proportions of lard. After weaning, calves on T1 diet had increased body weight, average daily weight gain (57-89 days), heart girth, and height at withers compared to calves on milk replacer diets. In the weaning phase, feeding T2 to calves resulted in higher body weight gain than those fed T3 and T4 diets while no difference was observed comparing T2 andT1.